Maslennikov, S. N., Finkel, M. I., Antipov, S. V., Polyakov, S. L., Zhang, W., Ozhegov, R., et al. (2006). Spiral antenna coupled and directly coupled NbN HEB mixers in the frequency range from 1 to 70 THz. In Proc. 17th Int. Symp. Space Terahertz Technol. (pp. 177–179). Paris, France.
Abstract: We investigate both antenna coupled and directly coupled HEB mixers at several LO frequencies within the range of 2.5 THz to 70 THz. H20 (2.5+10.7 THz), and CO2 (30 THz) gas discharge lasers are used as the local oscillators. The noise temperature of antenna coupled mixers is measured at LO frequencies of 2.5 THz, 3.8 THz, and 30 THz. The results for both antenna coupled and directly coupled mixer types are compared. The devices with in—plane dimensions of 5x5 ,um 2 are pumped by LO radiation at 10.7 THz. The directly coupled HEB demonstrates nearly flat dependence of responsivity on frequency in the range of 25+64 THz.
|
|
Ozhegov, R., Morozov, D., Maslennikov, S., Okunev, O., Smirnov, K., & Gol'tsman, G. (2004). Submillimeter wave range imaging system for registering human body radiation and finding out the things covered under clothes. In Proc. 3rd Int. exhibition and conf. Non-Destructive Testing Equipment and Devices. Moscow.
|
|
Ozhegov, R., Maslennikov, S., Morozov, D., Okunev, O., Smirnov, K., & Gol'tsman, G. (2004). Imaging system for submillimeter wave range. In Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10). Moscow.
|
Ozhegov, R. V., Gorshkov, K. N., Smirnov, K. V., Gol’tsman, G. N., Filippenko, L. V., & Koshelets, V. P. (2010). Terahertz imaging system based on superconducting integrated receiver. In Proc. 2-nd Int. Conf. Terahertz and Microwave radiation: Generation, Detection and Applications (pp. 20–22).
Abstract: The development of terahertz imaging instruments for security systems is on the cutting edge of terahertz technology. We are developing a THz imaging system based on a superconducting integrated receiver (SIR). An SIR is a new type of heterodyne receiver based on an SIS mixer integrated with a flux-flow oscillator (FFO) and a harmonic mixer which is used for phase-locking the FFO. Developing an array of SIRs would allow obtaining amplitude and phase characteristics of incident radiation in the plane of the receiver. Employing an SIR in an imaging system means building an entirely new instrument with many advantages compare to traditional systems: i) high temperature resolution, comparable to the best results for incoherent receivers; ii) high spectral resolution allowing spectral analysis of various substances; iii) the local oscillator frequency can be varied to obtain images at different frequencies, effectively providing “color” images; iv) since a heterodyne receiver preserves the phase of the radiation, it is possible to construct 3D images. The paper presents a prototype THz imaging system using an 1 pixel SIR. We have studied the dependence of the noise equivalent temperature difference (NETD) on the integration time and also possible ways of achieving best possible sensitivity. An NETD of 13 mK was obtained with an integration time of 1 sec a detection bandwidth of 4 GHz at a local oscillator frequency of 520 GHz. An important advantage of an FFO is its wide operation range: 300-700 GHz.
|
Ozhegov, R. V., Okunev, O. V., Gol’tsman, G. N., Filippenko, L. V., & Koshelets, V. P. (2009). Noise equivalent temperature difference of a superconducting integrated terahertz receiver. J. Commun. Technol. Electron., 54(6), 716–720.
Abstract: The dependence of the noise equivalent temperature difference (NETD) of a superconducting integrated receiver (SIR) on the receiver noise temperature and the inputsignal level has been investigated. An unprecedented NETD of 13±2 mK has been measured at a SIR noise temperature of 200 K, intermediate-frequency bandwidth of 4 GHz, and time constant of 1 s. With a decrease in the input signal, an improvement in the NETD is observed. This effect is explained by a reduction in the influence of the instabilities of the receiver power supply and the amplification circuit that occur when the input signal is decreased.
|
Ozhegov, R. V., Gorshkov, K. N., Gol'tsman, G. N., Kinev, N. V., & Koshelets, V. P. (2011). The stability of a terahertz receiver based on a superconducting integrated receiver. Supercond. Sci. Technol., 24(3), 035003.
Abstract: We present the results of stability testing of a terahertz radiometer based on a superconducting receiver with a SIS tunnel junction as the mixer and a flux-flow oscillator as the local oscillator. In the continuum mode, the receiver with a noise temperature of 95 K at 510 GHz measured over the intermediate frequency (IF) passband of 4-8 GHz offered a noise equivalent temperature difference of 10 ± 1 mK at an integration time of 1 s. We offer a method to significantly increase the integration time without the use of complex measurement equipment. The receiver observed a strong signal over a final detection bandwidth of 4 GHz and offered an Allan time of 5 s.
|
Glejm, A. V., Anisimov, A. A., Asnis, L. N., Vakhtomin, Y. B., Divochiy, A. V., Egorov, V. I., et al. (2014). Quantum key distribution in an optical fiber at distances of up to 200 km and a bit rate of 180 bit/s. Bulletin of the Russian Academy of Sciences. Physics, 78(3), 171–175.
Abstract: An experimental demonstration of a subcarrier-wave quantum cryptography system with superconducting single-photon detectors (SSPDs) that distributes a secure key in a single-mode fiber at distance of 25 km with a bit rate of 800 kbit/s, a distance of 100 km with a bit rate of 19 kbit/s, and a distance of 200 km with a bit rate of 0.18 kbit/s is described.
|
Pentin, I. V., Smirnov, A. V., Ryabchun, S. A., Ozhegov, R. V., Gol’tsman, G. N., Vaks, V. L., et al. (2012). Semiconducting superlattice as a solid-state terahertz local oscillator for NbN hot-electron bolometer mixers. Tech. Phys., 57(7), 971–974.
Abstract: We present the results of our studies of the semiconducting superlattice (SSL) frequency multiplier and its application as part of the solid state local oscillator (LO) in the terahertz heterodyne receiver based on a NbN hot-electron bolometer (HEB) mixer. We show that the SSL output power level increases as the ambient temperature is lowered to 4.2 K, the standard HEB operation temperature.
|
Ozhegov, R. V., Gorshkov, K. N., Okunev, O. V., & Gol’tsman, G. N. (2010). Superconducting hot-electron bolometer mixer as element of thermal imager matrix. Tech. Phys. Lett., 36(11), 1006–1008.
Abstract: The possibility of using a matrix of sensitive elements on a 12-mm-diameter hyperhemispherical lens in a thermal imager operating in the terahertz range has been studied. Dimensions of a lens region acceptable for arrangement of the matrix, in which the receiver noise temperature varies within 16% of the mean value, are determined to be 3.3% of the lens diameter. Deviations of the main lobe of the directivity pattern are evaluated, which amount to ±1.25° relative to the direction toward the optimum position of a mixer. The fluctuation sensitivity of the receiver measured in experiment is 0.5 K at a frequency of 300 GHz.
|
Smirnov, K. V., Vakhtomin, Y. B., Divochiy, A. V., Ozhegov, R. V., Pentin, I. V., & Gol'tsman, G. N. (2010). Infrared and terahertz detectors on basis of superconducting nanostructures. In IEEE (Ed.), Microwave and Telecom. Technol. (CriMiCo), 20th Int. Crimean Conf. (pp. 823–824).
Abstract: Results of development of single-photon receiving systems of visible, infrared and terahertz range based on thin-film superconducting nanostructures are presented. The receiving systems are produced on the basis of superconducting nanostructures, which function by means of hot-electron phenomena.
|
Smirnov, K. V., Vakhtomin, Y. B., Divochiy, A. V., Ozhegov, R. V., Pentin, I. V., Slivinskaya, E. V., et al. (2009). Single-photon detectors for the visible and infrared parts of the spectrum based on NbN nanostructures. In Proc. Progress In Electromagnetics Research Symp. (pp. 863–864). Moscow, Russia.
Abstract: The research by the group of Moscow State Pedagogical University into the hot-electron phenomena in thin superconducting films has led to the development of new types ofdetectors [1, 2] and their use both in fundamental and applied studies [3–6]. In this paper, wepresent the results of the development and fabrication of receiving systems for the visible andinfrared parts of the spectrum optimised for use in telecommunication systems and quantumcryptography.
|
Lobanov, Y., Shcherbatenko, M., Semenov, A., Kovalyuk, V., Kahl, O., Ferrari, S., et al. (2017). Superconducting nanowire single photon detector for coherent detection of weak signals. IEEE Trans. Appl. Supercond., 27(4), 1–5.
Abstract: Traditional photon detectors are operated in the direct detection mode, counting incident photons with a known quantum efficiency. Here, we have investigated a superconducting nanowire single photon detector (SNSPD) operated as a photon counting mixer at telecommunication wavelength around 1.5 μm. This regime of operation combines excellent sensitivity of a photon counting detector with excellent spectral resolution given by the heterodyne technique. Advantageously, we have found that low local oscillator (LO) power of the order of hundreds of femtowatts to a few picowatts is sufficient for clear observation of the incident test signal with the sensitivity approaching the quantum limit. With further optimization, the required LO power could be significantly reduced, which is promising for many practical applications, such as the development of receiver matrices or recording ultralow signals at a level of less-than-one-photon per second. In addition to a traditional NbN-based SNSPD operated with normal incidence coupling, we also use detectors with a travelling wave geometry, where a NbN nanowire is placed on the top of a Si 3 N 4 nanophotonic waveguide. This approach is fully scalable and a large number of devices could be integrated on a single chip.
|
Elezov, M. S., Ozhegov, R. V., Goltsman, G. N., & Makarov, V. (2017). Development of the experimental setup for investigation of latching of superconducting single-photon detector caused by blinding attack on the quantum key distribution system. In EPJ Web of Conferences (Vol. 132, 2).
Abstract: Recently bright-light control of the SSPD has been
demonstrated. This attack employed a “backdoor†in the detector biasing
scheme. Under bright-light illumination, SSPD becomes resistive and
remains “latched†in the resistive state even when the light is switched off.
While the SSPD is latched, Eve can simulate SSPD single-photon response
by sending strong light pulses, thus deceiving Bob. We developed the
experimental setup for investigation of a dependence on latching threshold
of SSPD on optical pulse length and peak power. By knowing latching
threshold it is possible to understand essential requirements for
development countermeasures against blinding attack on quantum key
distribution system with SSPDs.
|
Shcherbatenko, M., Lobanov, Y., Semenov, A., Kovalyuk, V., Korneev, A., Ozhegov, R., et al. (2016). Potential of a superconducting photon counter for heterodyne detection at the telecommunication wavelength. Opt. Express, 24(26), 30474–30484.
Abstract: Here, we report on the successful operation of a NbN thin film superconducting nanowire single-photon detector (SNSPD) in a coherent mode (as a mixer) at the telecommunication wavelength of 1550 nm. Providing the local oscillator power of the order of a few picowatts, we were practically able to reach the quantum noise limited sensitivity. The intermediate frequency gain bandwidth (also referred to as response or conversion bandwidth) was limited by the spectral band of a single-photon response pulse of the detector, which is proportional to the detector size. We observed a gain bandwidth of 65 MHz and 140 MHz for 7 x 7 microm2 and 3 x 3 microm2 devices, respectively. A tiny amount of the required local oscillator power and wide gain and noise bandwidths, along with unnecessary low noise amplification, make this technology prominent for various applications, with the possibility for future development of a photon counting heterodyne-born large-scale array.
|
Kovalyuk, V., Ferrari, S., Kahl, O., Semenov, A., Shcherbatenko, M., Lobanov, Y., et al. (2017). On-chip coherent detection with quantum limited sensitivity. Sci Rep, 7(1), 4812.
Abstract: While single photon detectors provide superior intensity sensitivity, spectral resolution is usually lost after the detection event. Yet for applications in low signal infrared spectroscopy recovering information about the photon's frequency contributions is essential. Here we use highly efficient waveguide integrated superconducting single-photon detectors for on-chip coherent detection. In a single nanophotonic device, we demonstrate both single-photon counting with up to 86% on-chip detection efficiency, as well as heterodyne coherent detection with spectral resolution f/f exceeding 10(11). By mixing a local oscillator with the single photon signal field, we observe frequency modulation at the intermediate frequency with ultra-low local oscillator power in the femto-Watt range. By optimizing the nanowire geometry and the working parameters of the detection scheme, we reach quantum-limited sensitivity. Our approach enables to realize matrix integrated heterodyne nanophotonic devices in the C-band wavelength range, for classical and quantum optics applications where single-photon counting as well as high spectral resolution are required simultaneously.
|
